Application of an image to a label surface of a computer disk, such as an optical disk (CD, DVD, etc.) can be accomplished by “burning” the image into a coating of thermally reactive material previously applied to the label surface of the disk. The laser ordinarily used to read or write data from/to the information side of the disk can be used to heat portions of the coating associated with pixels of the image to result in a thermal reaction and creation of the image. The laser is carried by a sled, which is configured to move the laser to each of a number of tracks. By turning the laser on and off, a concentric ring of pixels can be formed in the coating applied to the label area of the disk.
Unfortunately, in most applications, the number of tracks at which the sled is configured to stop is insufficient to result in the resolution required for desirable image quality. Images created where the number of available tracks is too small to support the desired resolution appear to have a narrow annular region or ring of un-reacted coating between each ring of pixels. One possible solution is to reduce disk speed enough that the time the laser spends on each pixel is sufficient to result in “blooming,” i.e. the expansion of the pixel due to reaction of coating material adjacent to the pixel. However, this requires more time than many users are willing to spend; also, while the larger pixels fill the narrow annular regions of un-reacted coating, the overall resolution is not improved due to the large pixel size.
As a result, while images created using a thermally reacting coating on a disk have benefit, there is a need to increase the resolution of such images.